[codex] apply dynamic contrast to text blocks

[chaochaoweb3]

Fixes #966.

Summary

• add the existing dynamic-contrast class to custom text block output
• keep the existing button-text styling intact

Validation

• git diff --check
• php -l resources/views/components/pageitems/text-display.blade.php (not run: php is not installed in this local environment)

[chaochaoweb3]

Rebased this onto the latest upstream main, corrected the commit author metadata, and marked it ready for review. I also triggered a fresh Scrutinizer run; it still reports repository-level analysis errored / tests failed with no artifacts exposed, and the Scrutinizer API shows the tracked main build is already failed. Local validation available here was git diff --check.